Welcome to the Physical Analytics Group!
The research focus of our group is material identification and characterization, as well as depth profile analysis of:
- Conductive as well as non-conductive inorganic materials
- ceramic products
- Multilayer systems
by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS).
© Florian Fahrnberger
ToF-SIMS is known to be a very versatile, extremely sensitive technique that provides detailed information on the elemental as well as on the molecular composition of all kinds of solid surfaces with extremely high sensitivity (down to ppb).
The bombardment of a surface with energetic primary ions leads to the emission of atoms, clusters, intact molecules and fragments from the uppermost monolayer of a surface, and the ionized fraction of the emitted particles can be analyzed by mass (mass resolution: >15 000).
ToF mass spectrometry is a pulsed primary ion beam technique and based on the fact that secondary ions with the same energy, but different masses, travel with different velocities. Measuring the flight time for each ion over a fixed distance allows the determination of its mass.
The time-of-flight technique offers parallel detection of all secondary ion species with ultra-high transmission and high mass resolution. This technique can be used for virtually all kinds of conductive and non-conductive materials. In the ion microprobe mode, a highly focused ion beam is scanned over an area of interest and complete spectra are recorded for every pixel. In this way, images can be acquired for all elements, including hydrogen and molecules, in parallel with high sensitivity. For a well-controlled removal of surface layers, a second ion beam with low energy sputter ions like oxygen, cesium (500 eV - 2000 eV) or cluster ions is simultaneously used in order to measure depth profiles of all species with high depth resolution in the nanometer range (dual beam mode).